1. Field of the Invention
The present invention relates to a developing apparatus used for copying machines, laser printers, and facsimiles, and a developer cartridge used for the developing apparatus.
2. Description of the Related Art
There are two types of developing apparatus with two-component developer (carrier and toner). One of them is provided with a single developer tank for two-component developer. In such developing apparatus it is necessary to supply first developer (carrier only or a mixture of a carrier and a toner) and second developer (toner) in regular order. A developer cartridge in which the first developer and the second developer are separately involved and sealed so as to be easy to supply in regular order these developers and a developing apparatus with such the developer cartridge are disclosed in Japanese Patent Application Laid-Open Publications Nos. 60 (1985)-165676, 61 (1986)-93469, and 61 (1986)-93470.
Another type of developing apparatus includes a first developer tank for the first developer and a second developer tank for the second developer. In such latter developing apparatus it is not necessary to be provided with a mechanism for supplying in regular order the developers to the developing apparatus.
However, when a user opens a lid of the supplying opening for initial setting before use or for replenishment of the second developer in use so as to supply the developer, there is given such a problem that the second developer may be introduced into a developer tank through the first developer supplying opening by mistake.
In addition, on the contrary, there is such a problem that the first developer may be introduced into the second developer tank.